The present invention relates to a data tape recorder for recording digital information on a magnetic tape and for reproducing digital information from the tape, and more particularly to a tape recorder having a data compressor/expander, which is capable of recording and reproducing digital information for a long time with a multichannel.
Presently, a digital recording and reproducing system such as a DAT (Digital Audio Tape) system which records and reproduces audio signals by digitally processing the signals, is divided into two main classes: normal mode and long time mode. The normal mode has a sampling frequency of 48 KHz and two channels of 16 bits, while long time mode has a sampling frequency of 32 KHz and two channels of 12 bits.
If the long time mode is permitted in the above DAT system, the recording and reproduction with a 4 mm tape (60 minutes) is possible at a maximum of four hours. Since the sampling frequency of the long time mode is 32 KHz, an actual audio bandwidth becomes about 14.5 KHz. And since the DAT has 12-bit quantization, the tone quality is deteriorated in comparison with 16-bit quantization. That is, when recording the audio signals for a long time with a multichannel, there is a disadvantage in that the tone quality is degraded.